oe geneva



A. ISLIKER.

TWO-STROKE INTERNAL COMBUSTION ENGINE.

APPLICATION F|LEDJUNE25,1919.

1,336,232. Patented Apr. 6, 1920.

NITEI) STATES uPA'IENT OFFICE.

.ALBERT ISLIKER, OF GENEVA, SWITZERLAND, ASSIG-NOR 0F ONE-HALF T0 MOTOSACOCHE SOCIETE ANONYME, 0F GENEVA, SWITZERLAND.

TWO-STROKE INTERNAL-COMBUSTION ENGINE.

Application led June 25, 1919.

To all ywhom it may concern:

Be it known that I, ALBERT ISLIKER, citizen of Switzerland, residing at Geneva, Canton of Geneva, in the Confederation of Switzerland, have invented certain new and useful Improvements in Two-Stroke Internal-Combustion Engines, of which the following is a specification.

The present invention relates to two stroke internal combustion engines comprising like other known machines of this kind at least one pair of motor cylinders on opposite sides to each other of the crankpit, at least one pump for the purpose of sending the combustible mixture into the cylinders before the compression of the same and at least one air pump for scavenging out the cylinders, the whole arranged in such a way that during the scavenging and the filling of the cylinders with combustible a certain quantity of pure air will be sent into the same and afterward a gaseous mixture of air and combustible mixture.

rl`he distinguishing feature of this engine however is, that the two pumps are formed by the pit of the crank shaft, this chamber being divided by a partition wall set vertically to the shaft into two separate chambers and that said pumps are adapted without the kaid of any special distributing means to cause the filling of the cylinders firstly with pure air and then with gaseous material of air and combustible mixture.

The suction inlet of the pump of combustible mixture may be provided with a contracted passage wav which is intended to revent the pump during the suction stage of filling entirely with combustible mixture and so as to cause the same to suck in also some pure air through a communicating port between the canals leading to the motor-cylinders which canals form the inlets for the combustible mixture and the air for scavenging the cylinders.

The pump for pure air may be of greater volume than that of the combustible mixture or may present a smaller dead space than the dead space of the pump for the combustible mixture. The distributing ports serving for admitting combustible mixture into the cylinders may have a smaller length parallel with the movement of the pistons. than the ports for admitting the pure air Specification of Letters Patent.

Patented Apr. 6, 1920.

Serial No. 306,721.

and may be freed later on during the motor stroke of said pistons. The pure air may be sent to the suction inlet of the air pump from a device furnishing compressed air.

The canals leading from the two pumps to one of the motor cylinders and letting pass the combustible mixture and the air for scavenging purposes may be shut off by a checking device in order to give the facility of putting the corresponding motor cylinder out of service. The motor may also be provided with a device for regulating the sucked-in quantity of combustible mixture and of pure air of the pumps.

The annexed drawing represents one working example of the motor and a modified detail of the same.

Figure 1 is a vertical length section of this working form.

Fig. 2 a cross-section of one of the cylinders.

Figs. 3 and L1 are horizontal sections on lines A-A, B-B of Fig. 1, the connecting rods being omitted.

Fig. 5 is a partial vertical section of the modified detail.

In the form of the invention shown in Figs. 1 to 4 there are two motor-cylinders 1, 2, whereof the parallel axes are in the same horizontal plane, but do not coincide and the open ends of which face each other. These cylinders are rigidly connected with the crank-pit 3 of the engine. This crankpit carries the bearings of a crank shaft 4 with the two cranks set at 180 with regard to each other and each connected by a rod 5 or 51 with the pistons 6 or 61 moving within cylinders 1. 2. In the walls of these cylinders rthe inlet-ports 10a and 11a are provided for the combustible mixture and the outlet-ports 12, 12b for the gases of combustion. All these ports are controlled by pistons provided with deiiectors for deflecting the incoming gases, spark plugs 16a, 16beffectthe iring of the combustible mixture.

One of the chambers 21 of the crank pit 3 acts as a pump for the combustible mixture and it communicates to this end with the chamber 19 to the right of the cylinder 1 by means of an opening 20 made laterally in a wall of the crank-pit 3 and through which the connecting rod 5 passes. The chamber 19 may be put in communication with a all neck Il?)d by means of the ports 7 controlled by the piston G, said neck leading to the carbureter.

Canals 8b, 9b leading from the chamber 21 respectively to ports 10b, 1lb are provided in the walls of cylinders l, 2 and serve for the introduction of the combustible mixture into the cylinders before the compression and under the control of the pistons 6, 61. The dead ace of this pnmp is considerable as it is constituted by the interior volume of the hollow piston 6 and by the chamber 21. (in the other part a dilfuscr of the carburetor, producing a rich combustible mixture presents a passage way small enough that the pump may not be filled entirely with combustible mixture at the suction stroke of this pump. l

Thepump furnishing the needed air for the scavenging is formed by the chamber 9A- of the crank-pit 3, said chamber coinmunicating with the left side chamber 22 of the cylinder 2 by means of an opening 23 made laterally in the wall of the crankpit 8 and forming the passage-way for the connecting-rod 51. In the wall of cylinder 2 there are also port-holes 7b controlled by the piston G1 and connected to a neck 13" communicating with the atmosphere and provided if needed with a screen. Tfhe chamber E24 communicates with canals 8, 9a leading` to the ports 10, l1 cut within the walls of cylinders l, 2 serving for the introduction. of air for scavenging purposes into said cylinders and controlled by the pistons (l, G1. In order to make the dead space of thev pump for air perceptibly smaller than that of the pump for the mixture, the piston 61 is provided with an interior partition 'all 27 and the crank pit l fitted on 'the outside with a jointed body 2S projecting into chamber Q2, see Fig. 4f. On the other side the passage-way of the dilfuser of the carburetor has a smaller cross-section than that of the air-inlet into the neck 131. The ports l()a and l0*J on one part and the ports l1, and 1lb on the other part, are in the same vertical plane with the axes of the cylinders and have the same axial length, so that they are covered and uncovered simultaneously by the pistons; the exhaust ports 12a, 12b however are uncovered by the pistons somewhat earlier than the said ports.

rlhe canals 8 and 8b, 9 and V9" communicate with each other quite close up to these ports owing to passageways '25, 2,6 provided within the' partition walls separating the same.- f

The two chambers 21, 5211- of the crank-pit are separated by a `dislr-shaped plate 1S made in one piece with the crank-shaft 4 and provided at its rim with an annular groove jointing with an annular flange of the crank-pit 8. Thus a relatively tight joint is obtained here, which tightness is not absolutely necessary.

Vithin the necks 13a and 13b checking devices have been provided fer, such as butterfly-valves for instance, which are operated from a common shaft ll carrying a handle l5. A contrivance not represented in the drawing makes it possible to vary by means of this shaft the composition of the gases admitted to the motor-cylinders. Besides a checking-member 17 is arranged within the canals 9, 9b by means of which member the cylinder 2 may be cut out of service.

The operation of this form of the invention is as follows: Supposing the pistons G. G1 are both at their interior end position and are aboutl to move outwardly, they will both compress within the combustion chambers of their cylinders the combustible mixture which has previously been admitted there and will at the same time create a certain vacuum within the chambers 2l, 2l and finally will uncover the port-holes 7, 7l. Through the first of these ports a rich combustible mixture coming from the carbureter Will enter the chamber 2l. The quantity of mixture thus sucked in, owing` to the small passage-Way of the diffuser of the carburetor, will not be sufficient to lill the chambers 21 and 24e. Therefore a supply of fresh air will also he admitted this air coming 'in through the neck 13", the ports 7b, the chambers Qa. Qi, then on one side through canal 8a, passage-way 25, and

canal 8b, and on the other side through the canal 9a, passage-way 2G and canal. 9b. The four canals 8, 8b, 9', 9b therefore contain only fresh air.

The combustible mixture compressed dur-- ing the prccedin 1v stroke within the comlnistion chambers will then be fired by the spark plugs 16a, 1Gb, and will exphide and expand moving the pistons G. 61 toward the inside until the gases of combustion can escape through the ports l2, 12b. These pistons will compress at the same time the conibustible mixture within chambers 1.9, 2l., and the pure air shut up within the chambers 22, 24. As the dead space for the pump of combustible mixture is much greater than the space within the air pump the compression given by the first is not so considerable as that given by the second, to such a degree that a new quantity of fresh air will4 le pressed at this moment into the chamber 2l through 8", 25, 8b and 9;, Q6. 1lb. These canals and these passages will there foro continue to contain fresh air and the portions of chainber 2l adjoining the canals Sl) and D" will also contain pure air. The pistons (l, (31 will lirst uncover the portsl '19, l2, which will allow the gases of the combustion within the cylinders to assume a pressure quite equal to the atmospheric pressure and then it will uncover the ports 10a, 10b, 11a, and 11b. Through these latter will pass lirst the fresh air contained within the canals Sa, Sb, 9, 9b, one part of the air of chamber 2% and thc air within chamber 21 next to the canals.

The scavenging of the gases of combustion has thus been accomplished. Finally the rest of the contents of chambers 21 and 21 a mixture of combustible and fresh air will be delivered into the cylinders until equilibrium of pressure has been established between the interior of these cylinders and the pumps. A mixture of this mixture and of fresh air will be formed for a new charge. Thus the first portion of the incoming gases of the cylinders, a portion of which is lost with the escaping gases of the combustion, will be composed almost solely of air and the quantity of combustible taken along by the rst gases will be very small. Any contact between the gases of combustion or the burning mixture and the fresh mixture avoided, as is also the possibility of return flames into the crank-pit and carbureter.

As it results from the description in the above and from the Figs. 1 to 4l, this working form will have the effect that the gases introduced into the cylinders 1, 2, will be first a certain quantity of pure air and then a quantity of gas composed of air and of combustible mixture simply by the constructive arrangement of the two pumps without using any special distributing member. The sought-for result has therefore been obtained at little expense.

The motor may turn in both directions likewise. The regulating of the motor is effected by means of devices mounted within the passages 13, 13". If the load is small the cylinder' 2 may be cut out by means of the checking member' 17 in order to save fuel.

The two chambers of the crank-pit 2 may be provided with means for recollecting the lubricant spattered by the rods and cranks of the shafts, thus avoiding its being taken along with the combustible mixture and the fresh air and passing into the combustion chambers of the cylinders 1, 2. The portholes 10b and 11b may have a smaller axial length than the ports 10n and 10b as is indicated by dotted lines for the port 11b in Fig. 3 and arranged so as to have the pistons uncover these ports later than the ports 10n and 11n. In the case of direct communica.- tions 25, 26 between the canals 8n and Sb, 9 and 9b are omitted, communications may be substituted therefor leading from the inside of the cylinders at the moment when the ports 10a and 10b, 11a and 11b are both .uncovered. The scavenging will also occur, but less eifectually than before. Moreover the useful stroke of the pistons 6, 61 is diminished as the ports 1()b and 1lb will be earlier uncovered by the said pistons.

According to Fig. 5 the communication between the canals 8a and 8b, 9 and 9b takes place owing to a hollow 29 provided within the pistons 6 or G1 and corresponding at the given moment either with the ports 10 and 10h, or with the ports 11n and 11b.

If the axial length of the ports is diminished in this case, in order to reduce as much as possible the reduction of the useful stroke also their total area will be reduce-Jl which is not of any benefit.

The motor may have more than one pair of motor cylinders opposite to each other and be combined with more than one pump for the combustible mixture and also with more than one air pump for scavenging purposes.

The partition wall between the two chambers of the crank pit may also be a stationary wall provided with a bearing for the crank-shaft.

Claims:

1. In an internal combustion engine. com prising a cylinder, a piston in the cylinder, a closed crank pit. there being an explosion chamber at the outer side of the piston, an intake chamber at the inner side of the piston, and gas and air chambers in the closed crank pit, a. crank shaft, a crank extending through a wall separating the intake chamber from the chambers in the crank pit, and means whereby air and gas are drawn into said chambers by the operation of the piston, there being intake and exhaust ports in the cylinder and passages .from the gas chamber to the inlet ports with communications between the passages and the air chamber in the crank pit so that when the intake an'd exhaust ports are open, air is first admitted to the cylinder to scavenge the same before the fresh gas is admitted thereto.

2. In an internal combustion engine, comprising a plurality of cylinders in pairs, with each pair of cylinders in alinement, a piston in each cylinder, a closed crank pit between the cylinders, there being air and gas chambers provided in the closed crank pit, and means whereby gas is drawn into the gas chamber and air into the air chanr ber by the operation of the said pistons, there being intake and exhaust ports in said cylinders, and passages from the gas chamber to the inlet portsin the cylinders with connections between said passages and the air chamber in the closed crank pit, so that when the intake and exhaust ports are open, air is first admitted to the cylinders to scavenge the same before the fresh gas is admitted thereto.

3. In an internal combustion engine, com prising a plurality of cylinders in pairs, with each pair of cylinders in alinement, a

piston in each cylinder, there being an eX- plosion chamber at the outer side of the piston, and an intake chamber at the inner side of the piston, a closed crank pit between each pair of cylinders and having separated gas and air chambers therein, a crank shaft, cranks extending between the crank shaft and the respective pistons, and means whereb in the o eration of one )iston 0`as is drawn into the intake chamber associated therewith and delivered to the Lgas chamber in the crank pit, and in the operation of the complementary piston, air is drawn into the intake chamber associated therewith and delivered to the air chamber in the crank pit, there being intake and exhaust ports in said cylinders and passages from the gas chamber in the crank pit to the intake ports with communications between the same and the air chamber in the crank pit so that when the intake and exhaust gorts are open, air is first admitted to the cylinders to scavenge the same before fresh gas is admitted thereto.

t. In an internal combustion engine, comprising' a plurality of cylinders, a piston in each cylinder, there being; an explosion chamber at the outer side of the piston, and an intake chamber at the inner side of the piston, a closed crank pit having sepa-r' t gas and air chambers therein, the capri. w of the air chamber and passages leading` therefrom being' greater than that of the said gas chamber, a crank shaft, cranks extending between the crank shaft and the respectiv'e pistons, and means whereby in the operation of one piston gas is drawninto the intake chamber associated therewith and delivered to the gas chamber in the crank pit, and in the operation ofthe complementary piston, air is drawn into the-intake chamber associated therewith and delivered to the air chamber in the crank pit, there beingintake and exhaust ports in said cylinders, and passages from the gas chamber in the crank pit to the intake ports with communications between the same and the air chamber in the crank pit so that when the intake and exhaust ports are open, air is first admitted to the cylinders to scavenge the same before fresh gas is admitted thereto.

In an internal combustion engine, comprising a plurality of cylinders, a piston in each cylinder, there being?, an explosion chamber at the outer side of the piston, and an intake chamber at the inner side of the piston, a closed crank pit having` separated gas and air chambers therein, the capacity of the air chamber and passages leading therefrom being` greater than that of the said pas chamber, a crank shaft, cranks eX- tending between the crank shaft and the respective pistons, means whereby in the operation of one piston gas is drawn into the intake chamber associated therewith and delivered to the gas chamber in the crank pit, and in the operation of the complementary piston, air is drawn into the intake chamber associated therewith and delivered to the air chamber in the crank pit, there being intake and exhaust ports in said cylinders, and passages from the gas chamber in the crank pit to the intake ports with communications between the same and the air chamber in the crank pit so that when the intake and exhaust ports are open, air is rst admitted to the cylinders to scavenpge the same before fresh gas is admitted thereto, and means for controlling the admission of the air and gas to the said cylinders and the admission of air and gas to the said intake chambers.

ln testimony whereof I affix my signature in presence of two witnesses.

ALBERT ISLIKEB.

lWitnesses EDM. EMMANUEL, D. RAD DE VERNDENBURG. 

